Nowadays, more and more sensors are used. Many of these sensors measure environmental parameters such as CO2, moisture, temperature or smoke. However, these sensors naturally do not measure the parameters of the room but the parameters within the respective device into which they are integrated. Then, an attempt is made to approximately extrapolate the parameters of the room air from the measuring signal of the sensor by means of complicated algorithms, which only partially succeeds.
Detection of gases such as CO, N2O or VOC as well as of water contents and the gas composition in our surroundings is in the interest of many people.
In addition, most people would like to instantly sense air polluting gases, fine dust and allergenic particles such as pollen at their location or receive early warnings of allergenic substances and hazardous gases. Moreover, the detection of odors such as breath alcohol, bad breath and many other odors is of interest.
Sensors are available for many of the applications mentioned. Although many of the available sensors (e.g., for humidity, volatile organic compounds VOC, CO or NO) or the sensors based on organometallic, optical or resonance principles comprise form factors and an appropriate cost-efficiency for use with portable devices, the commercial use is only possible in a limited extent, since the gas, the odor or the fine dust may not be delivered quickly and reliably to the sensor in a portable device in all sensor principles.
However, this is necessitated in order to provide the user with a meaningful and fast measurement result. Reliable data for gas measurements may provide meaningful gas overviews of the surroundings, e.g., air pollution along streets or in large cities, respectively, or pollen maps for people suffering from allergy.
In some cases, sensors are installed in bulky, stand-alone units. In some cases, mouthpieces have to be used with these devices, which many people do not like. An additional problem is that stand-alone devices with sensors necessitate display and computing capabilities, which incurs additional costs.
Such a specialized portable gas measuring device is known from WO 2015/104221 A1. The Reference refers to a sensor unit for a gas measuring device for detecting a gas. The transportable gas measuring device serves to monitor gases and vapors, in particular toxic gases in industrial environments. In general, it is about the change in a physical-chemical property of the receptor interacting with analyte molecules at the molecular level. In this connection, WO 2015/104221 A1 describes a combination of a pressure-tight measuring channel, a gas inlet, a gas outlet, a pump unit for evacuation, a gas sensor, a heating unit for the gas sensor and a sensor unit with a regeneration mode and a measuring mode.
As mentioned at the outset, the gas measuring device known from WO 2015/104221 A1 is a specialized apparatus intended exclusively for measuring gases in the ambient air. Such apparatuses provide good and reliable measurement results. However, such apparatuses necessitate a certain amount of time during which the gas sensor technology calibrates itself to provide a sufficiently reliable result. Such known devices are therefore not immediately ready for use, especially in cases where the conditions of the surroundings rapidly change. For example, this is the case when the device is moved from an outside area into an inside area such as a living room. In this case, known apparatuses necessitate a certain amount of time to “acclimatize”, so to speak, which may be up to several minutes.
However, fast response times of the gas sensors are desirable for many applications of portable electronic devices, e.g., in the case of a rapid sensing of people by means of gas sensors, in the case of fire detection sensors or to sense when a person is entering a building. When taking this knowledge into account, the manufacturers of gas measuring devices would have to mount their sensors directly onto the housing surface in order to obtain a rapid signal. However, this is uneconomical or unfavorable for several reasons.
On the one hand, arranging the sensor on one of the circuit boards in the housing increases the assembly requirements and, inevitably, the associated assembly costs. In addition, if mounted directly onto the housing surface, there is the risk of damage to the sensor by external influences. On the other hand, if the sensor is installed on the outside of the gas measuring device, the housing may no longer be smooth. Moreover, if many gas sensors and other components (e.g., circuit boards, displays, etc.) are to be mounted close to the air inlet of the gas measuring device, there may not be enough space available.